Aruco Marker Corners Occasionally Mislocated
I have a situation where my Aruco markers are occasionally mislocated so that the marker is undersized. When this happens (<5% of images), it happens to all the markers in an image.
Here's an example of two consecutive frames:
Frame 30 is correctly located: raw image zoomed in with red stars on corners
Frame 31 with markers identified as undersized (all three are similar): raw image zoomed in with corners
I'm doing this using the Matlab wrappers from https://github.com/kyamagu/mexopencv
Edit: identical results for the python wrappers
Everything uses defaults, here's my Matlab code:
dictionary = {'Predefined', '6x6_250'};
img=imread('frame31bad.png');
%detectorParams.cornerRefinementMethod = 'Subpix';
detectorParams.cornerRefinementMethod = 'Contour';
%detectorParams.cornerRefinementMethod = 'None';
[corners, ids, rejected] = cv.detectMarkers(img, dictionary,...
'DetectorParameters',detectorParams)
figure(2)
imshow(img)
hold all
for i=1:numel(corners)
for j=1:4
plot(corners{i}{j}(1),corners{i}{j}(2),'r*')
end
end
hold off